package _33define;

import java.util.ArrayList;

public class Demo {
    public static void main(String[] args) {
        String s="abcd";
        String t="baedc";
        ArrayList<Character> charList=new ArrayList<>();
        for (char c : s.toCharArray()) {
            charList.add(c);
        }
        for (char c : t.toCharArray()) {
            if (!charList.contains(c)){
                System.out.println(c);
                break;
            }
        }
    }
}
